Virtual
Reality Conquers Sense Of taste
Food
companies cooking up a novel product will soon be able to
check how elderly people will fare when they try to chew
on it, thanks to a device that mimics the taste and "mouthfeel"
of food.
Already,
virtual reality devices have been built that try to simulate
experiences for four of our five senses -- vision, hearing,
touch and smell. But the complexity of the sense of taste
has made it difficult for computers to conquer.
Taste
combines the feel of food in the mouth with chemical and
even auditory cues. Hiroo Iwata of the University of Tsukuba
in Japan and colleagues call it the "last frontier
of virtual reality".
But
it is a frontier they have now crossed. "The food simulator
is the first media technology that is put into the mouth,"
says Iwata.
Before
simulating a foodstuff, the team first measures and records
various phenomena associated with chewing it. One such parameter
is the force required to bite through a piece of the food.
A thin-film force sensor placed in a subject's mouth records
these forces. Biological sensors made of lipid and polymer
membranes record the major chemical constituents of the
food's taste. A microphone records the audible vibrations
produced in the jawbone while chewing. These parameters
serve as inputs to the food simulator. The mechanical part
of the simulator that is inserted into the mouth has cloth
and rubber covers, mainly for sanitary reasons, and is intended
to resist the user's bite in a similar way to the real foodstuff.
When someone chews the device, a sensor registers the force
of the bite and a motor provides appropriate resistance.
To augment
the experience, a thin tube squirts a mixture of flavourings
onto the tongue. The chemicals stimulate the five basic
taste sensations: sweet, sour, bitter, salty and umami -
the taste of monosodium glutamate. Meanwhile, a tiny speaker
plays back the sound of a chewing jawbone in the user's
ear.
Iwata
says that his team has successfully simulated many foods,
including cheese, crackers, confectionery and Japanese snacks.
One remaining step still to be tackled is to use a vaporiser
to deliver appropriate smells to the nose. The researchers
say their device is perfect for people designing new foods,
and may even allow young designers to experience the difficulty
older people may face in chewing food.
The
technology can also be entertaining -- for the researcher
at the controls, at least. By suddenly changing the properties
of a food in mid-chew -- from a cracker to a jelly, say
-- the result is uniquely funny, says Iwata.
Vibrating
pedal says
'Ease
off gas’
A
vibrating accelerator pedal that tells motorists when to
slow down could save them a substantial amount of money
in fuel bills. Most drivers waste fuel by braking for traffic
lights or other obstacles only at the last minute, but expert
drivers see that they will need to slow down and take their
foot off the throttle much sooner.
The
vibrating pedal is part of a prototype system that mimics
this approach by monitoring traffic, speed restrictions,
junctions coming up and so on, and then telling drivers
to ease off the gas.
The
principle is simple. If your car is travelling at, say,
80 kilometres per hour, it burns more fuel per kilometre
than if it is travelling at 50 kph. So if you know you have
to slow down from 80 to 50 kph in perhaps 300 metres, you
may as well decelerate straight away and drop to the lower
fuel-consumption rate.
The
vibrating alert system, from DaimlerChrysler -- which owns
Mercedes, Jeep and Smart, among others -- is designed to
help you save fuel this way. Trials with 70 volunteer drivers
indicate an average reduction of 11 per cent.
The
device is computerised, and combines measurements from several
sources to help it judge when the car will need to start
slowing down. It uses GPS to work out where it is on the
road network, but its map contains far more information
than those used in most satellite navigation systems for
cars: it includes speed limits, gradients and road curve
radii.
The
S-Class Mercedes automatic that has been fitted with the
prototype also has vehicle-detection radar so the driver
can tell when they are getting too close to cars in front.
A PC
mounted in the car assimilates these measurements and predicts
whether the car will need to decelerate, perhaps to take
a sharp bend. It calculates the optimum moment for the driver's
foot to leave the throttle and sends a signal to a small
actuator fixed under the pedal, which lightly vibrates a
small piston against the underside of the pedal rubber.
"It
simply alerts the motorist to the situation and gives him
or her a choice about what to do next." says Klaus-Peter
Kuhn of DaimlerChrysler's human-machine interaction group.
Vibration
alert was chosen because drivers react faster to it than
they do to dashboard lights. In DaimlerChrysler's tests
in Stuttgart, Germany, drivers took 2.0 seconds to react
to a light, but only 0.3 seconds to respond to a vibration.
There
is one hitch that might make it hard to sell the technology.
The fuel-saving benefits would not be shown on the official
fuel consumption figures for any car it was fitted to, since
efficiency figures are obtained from simple tests at different
speeds on a rolling road -- they do not take into account
the effects of corners, traffic or hills.
Unless
the tests are changed, says Kuhn, the company would not
be able to advertise the fuel savings, and there would be
less incentive to fit cars with the system. The firm is
now hoping for an overhaul of the tests to make this possible.
Butter
that not only spreads easily when cold, but also contains
a healthier balance of fats has been developed by researchers
tinkering with the diets of cows.
"To
be able to lift it out of the fridge and spread it is brilliant,
and knowing I'm doing myself less harm is even better,"
says Anna Fearon, who led the team which developed the spread
at the University of Belfast in Northern Ireland. "It
does taste like real butter too," she adds.
The
scientists altered the fat profile of the milk from which
the butter was made by adding rapeseed oil to the cow's
fodder. Fearon says that it would also be possible to make
cheese, ice cream and other dairy products from the "healthier"
milk.
Cows
consuming 600 grams of rapeseed (canola) oil every day produced
milk containing 26 per cent less palmitic acid, the "bad"
saturated fat which is thought to clog up arteries. At the
same time, beneficial "unsaturated" fats like
those in some margarines went up substantially. Oleic acid,
abundant in olive oil, rose by 35 per cent.
These
changes had another benefit - making the butter spreadable
at lower temperatures. Palmitic acid melts at 62°C,
whereas oleic acid melts at just 16°C, and is soft at
fridge temperatures of 4°C.
Fearon
says that altering the fat composition was not simple, as
pure rapeseed oil can harm vital bacteria in the rumen,
the cow's forestomach where grass is pre-digested.
To
avoid this, Fearon's team added the oil in the form of raw
seeds. These pass straight through the rumen without disturbing
the bacteria, before being digested later. None of the cows
in the trials suffered any adverse effects, she says. The
team also showed the more rapeseed they gave the cows, the
better the balance of fats.
Fearon's
team reported its findings in a journal on Monday, the first
disclosure of the science behind the "Pure Butter"
product made by Dromona Quality Foods of Cullybackey, County
Antrim. It is already on sale in Northern Ireland and at
Marks and Spencer outlets in Britain.
"For
butter eaters like myself, improving the fatty acid profile
is beneficial," says Jackie Brown, senior research
scientist at the Institute of Food Research in Norwich,
Norfolk. "But it still has more saturated fat than
some of the margarines."
Also,
some margarines are richer in the polyunsaturated fats which
decrease the amount of artery-clogging cholesterol in blood.
"Although this butter is greatly improved and contains
mono-unsaturated fats, it still is not the healthiest option
for those with high blood cholesterol," says Brown.
Source:
Newscientist.com
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